Raising pots for root crop seedlings

ABSTRACT

Raising pots for root crop seedlings which are produced by molding a mixture comprising unboiled bamboo fiber, a boiled fiber material of a grass plant, lespedeza, etc., a carbonized vegetable material having been carbonized by heating and urea optionally together with a silicon dioxde powder.

INDUSTRIAL FIELD OF THE INVENTION

The present invention relates to a seedling pot for raising root cropseedlings such that a main material and a supplementary material addedthereto do constitute the seedling pot. The main material is chosenherein from nonwoody fibers, with the supplementary materialfacilitating the desired healthy growth of any particular seedlings,also resolving the pro-blems of environmental pollution.

PRIOR ART

As known widely, the prior art seedling pots have usually beenflower-pot miniatures molded using a proper plastics sheet such as apolyvinyl chloride resin. Those plastics pots are cheap but cost muchlabor because the seedlings should be removed from the pots, prior totransplantation to a farm or larger pots. A clod of soil around the rootof each seedling is likely to be broken to injure the root, therebyadversely affecting growth of the seedling thus transplanted. Theburning of those discarded seedling pots has undesirably causedenvironmental pollution. In some proposals that have been made in viewof these problems and are going to be em-ployed in the art, certainagricultural and/or forestry wastes are salvaged to manufacture seedlingpaper-made pots.

After use of such papery pots already proposed and economically made ofthose natural wastes, they can be left on and/or in the earth. They willundergo a fast biological decomposition in situ, resolving one of thedrawbacks inherent to the prior art plastics pots. Thus, they may beexpected to be advantageous insofar as assessed on their economical andenvironmental merits. Material composition and configuration of suchpapery pots have however not been researched, though they must affect ongrowth of the respective botanical kinds of seedlings. No attention hasbeen paid on what requirements the papery pots should meet for raisingthe particular seedlings that might be root crops, fruit crops (i.e.,fructifying vegetables) or green foliar vegetables. Under suchcircumstances, none of the already proposed type papery pots did proveuseful to raise all the kinds of seedlings. Therefore, it has been longand eagerly demanded to develop a seedling pot not only advantageouseconomically and environmentally but also capable of meeting particularrequirements which any desired type of seedlings being raised wouldshow.

DISCLOSURE OF THE INVENTION

An object of the present invention is therefore to provide a seedlingpot particularly adapted for use to raise the seedlings of farm productsthat are generally called root crops including radishes, potatoes,burdocks, lily bulbs and the like. The seedling pot, that will bemass-produced herein using inexpensive vegetable materials and certainother materials not widely utilized in this field, has to be designedand composed in principle such that growth of a taproot, an undergroundstem, a tuber or the like important organs will be facilitated. Also,this seedling pot that can inexpensively be manufactured herein assuggested above has to be tenacious, safe and harmless to handle. Whendiscarding this pot after use, it may usually be left in the earth so asto be ready for biological decomposition in situ, or may alternativelybe burnt without generating any toxic substance.

According to the present invention, a seedling pot for root crops may bemolded using a mixture of an unboiled bamboo fiber, a boiled fiber ofGramineae or Leguminosae plant (such as Lespedeza bicolor, viz.,Japanese bush clover), a carbonized plant material obtained by roastinga nonwoody plant, and urea as an additive. From another aspect, theinvention provides a seedling pot for root crops may be molded usinganother mixture of an unboiled bamboo fiber, a boiled fiber of Gramineaeor Leguminosae plant (such as Japanese bush clover), a carbonized plantmaterial obtained by roasting a nonwoody plant, urea as an additive, anda powder substantially consisting of silicon dioxide.

In the preferred embodiments, the first ingredient of the mixture of rawplant materials as mentioned above may be composed of about 7 to 10% byweight of an antibacterial bamboo fiber originating from bamboo stems,branches, skins and/or cores. Blended with this antibacterial bamboofiber may be about 50 to 60% by weight of the boiled fiber prepared froma ditch reed (viz., Phragmites communis) or Japanese bush clover, about20 to 30% by weight of the carbonized material prepared by roasting abuck-wheat chaff, tea dregs, oil cakes, or using already-roasted coffeegrounds (needing not be roasted again), and about 15% by weight of urea.This mixture will be heated and compressed in a mold at a temperature of180° C. or higher, preferably about 200° C., at a pressure of 3-6 kg/cm²and for a time of 24-30 sec. Such a molding process does not need anybinder such as a sizing agent that is generally used in the paper-makingmills, because hydrogen bonds acting between the fibers will firmlyadjoin them together to give a desired shape to the pot thus molded.Instead of direct thermal compression in the mold of a desired cavityshape, the bamboo fiber, the boiled fiber and carbonized plant materialmay alternatively be suspended first in water to form a slurry. Thisslurry will then be filtered through a paper-making screen, beforethermally pressed in a mold. The antibacterial bamboo fiber contained inthe peripheral wall of the seedling pot will retard and inhibit anylateral roots of the seedling from growing towards said wall. As aresult, the taproot of this seedling will preferen-tially receive andutilize the nutritive compounds that are present around it, therebyproducing an excellent root crop seedling.

By virtue of spontaneous and biological decomposition of the pots in theearth, they need no longer be removed when the seedlings aretrans-planted. Labor consumption for transplantation will thus be savedas com-pared with the case of using the conventional plastics pots. Thecarbon-ized material contained in the pot wall will provide a noticeableamount of carbon to react with urea so that nitrogen and/or itscompounds are pro-duced to serve as one of the nutritive substances.

About 2-5% by weight of silicon dioxide (SiO₂) may be added to thedescribed composition of seedling pots. A powder of quartz may be usedas the main component of said silicon dioxide expected to enablerepeated cultivation of the same crop on the same ground. It has beenreported that Fusarium bacteria would cause putrefaction of watery soilfractions, result-ing in inhibition of said repeated cultivation.However, the added silicon dioxide powder will induce wave propagationthrough the water in soil fractions, thereby protecting them fromputrefaction.

Similarly to the conventional flowerpots, the seedling pot as moldedabove may have through its bottom a central drainage hole (1). Outwardprotrusions (3) and outward grooves (4) do all surround the central holein order to prevent it from becoming clogged. The seedling pot will bebiologically decomposed in about two months, if left in the ground. Thisperiod will generally correspond to a time lapse from transplantation tothe point of time when the pot's periphery start to interfere with thelateral roots growing sideways. Length of such a time lapse doesnaturally depend on the sorts of crops, and perforations (2) formed inand through the periphery and/or bottom of seedling pot will be usefulto expedite biological decom-position thereof. The number of suchperforations may typically be one or more, and 12 (twelve) or more orless. About 2% by weight of a water repellent may be added to thecomposition of said pot so as to retard biological decomposition by afew or several months. Such a prolonged life of pot in the ground willbe convenient to cultivation of bulbous crops or to any grafted plants.

The seedling pot provided herein for raising root crops willauto-nomically vary its moisture content within a wide range of 7 to25%.

If ambient humidity rises, then the pot will absorb moisture, tending tolower its humidity. If contrarily ambient humidity descends, then thepot will desorb moisture, tending to increase its humidity. By virtue ofsuch an autonomical control of humidity, this pot will adjust itself toa temporary ambient dryness during usage for raising seedlings. Further,the seedling pot of the invention is superior to the polyvinyl chloridepots in its property of keeping warmth (18° C.-10° C.), making itselfsuited for use in cold zones.

The raw materials used herein to produce the seedling pot of thein-vention have been useless wastes, so that such cheaper materials willlower manufacture cost. Even if the pots have to be thrown away afteruse, they can be burnt at such lower temperatures that any trash burneror the like will neither be injured, nor generating any amount ofdioxines. In a case wherein the used pots are left in the grounds, theywill be biologically de-composed by bacteria and/or enzymes to therebygive certain nutritive compounds, thus contributing to soil improvementand environment purification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a seedling pot provided in a firstembodiment of the invention, the pot being designed for use to raiseroot crop seedlings;

FIG. 2 is a plan view of the seedling pot shown in FIG. 1;

FIG. 3 is a front elevation of the seedling pot shown in FIG. 1;

FIG. 4 is a perspective view of the seedling pot as shown in FIG. 1 andin use;

FIG. 5 is a perspective view of a seedling pot provided in a secondembodiment of the invention, the pot also being designed for use toraise root crop seedlings;

FIG. 6 is a plan view of the seedling pot shown in FIG. 5;

FIG. 7 is a perspective view of a seedling pot provided in a thirdembodiment of the invention, the pot being likewise designed for use toraise root crop seedlings; and

FIG. 8 is a plan view of the seedling pot shown in FIG. 7.

BEST MODES OF CARRYING OUT THE INVENTION

Now, the first embodiment of the present invention will be describedreferring to FIGS. 1 to 4. A material mixture for molding andconstituting the pot is composed of about 10% by weight of unboiledbamboo fiber, about 60% by weight of boiled fibers of ditch reed andJapanese bush clover, and about 30% by weight of roasted and carbonizedbuckwheat chaff, tea dregs and the like. The mixture further containingabout 15% by weight of urea, well blended therewith, is molded at 200°C., at a pressure of 3 kg/cm² for 24 sec. Hydrogen bonds cause thesefibers to firmly stick one to another to give a molded piece of theshape as a seedling pot. The seedling pot of the first embodimentresembles a flowerpot, and has in its bottom a central drainage hole 1,outward protrusions 3 and grooves 4 in communication with the hole. Theprotrusions 3 and grooves 4 alternating therewith are arranged inhorizontal directions, radially and outwardly from the central hole 1.This pot has 8 (eight) perforations 2 in its periphery, and one in eachof three radial outward grooves 4, thus the total number of thoseperforations is 11 (eleven). In manufacture, a primary molding step willproduce a circular flash continuing from a rim around the open top ofthis pot. Therefore, a secondary molding step will be conducted toremove such a flash and form at the same time the central hole and theperforations. FIGS. 1 to 3 show the appearance of this seed-ling pot,with FIG. 4 illustrating it in use and a seedling planted and growingtherein.

In a second embodiment as shown in FIGS. 5 and 6, unboiled bamboo stems,branches, skins and/or cores are ground to give chips finally forming apowder pulp. About 10% by weight of this powder pulp is mixed with about30% by weight of boiled ditch reed, about 30% by weight of boiledJapanese bush clover and about30% by weight of roasted and carbonizedbuckwheat. This mixture is then stirred in water within a dissolver soas to provide a suspension, before about 5% by weight of urea will beblended therewith to give a molding composition. A paper-making screenis used to form from this composition a web that is then molded at 200°C., at a pressure of 3 kg/cm² for 30 sec. A seedling pot thus obtainedas shown in FIGS. 5 and 6 has only in its periphery 12 (twelve)perforations 2. Al-though the kinds of raw materials and the conditionsfor molding same do differ from those in the first embodiment, theseedling pot of the second embodiment does nevertheless have a structureand show its performance, both within a scope of the present invention.

In a third embodiment shown in FIGS. 7 and 8, about 10% by weight ofbamboo fiber is mixed with about 60% by weight of ditch reed or Japanesebush clover and 30% by weight of roasted and carbonized buck-wheat ortea dregs. This mixture is blended with about 5% by weight of urea aswell as 2% by weight of quartz powder, before molded in the same manneras in the first embodiment so as to give a seedling pot as shown inFIGS. 7 and 8. 6 (six) perforations 2 are formed in the periphery. andarranged in a staggered pattern, and one perforation is formed in eachof the three protrusions 3 in bottom. Thus, the total number ofperforations 2 in this case is 9 (nine).

1. A seedling pot for raising root crop seedlings, the pot being amolded piece formed of a mixture of an unboiled bamboo fiber, a boiledfiber of Gramineae or Leguminosae plant such as Japanese bush clover,and a carbonized plant material obtained by roasting a nonwoody plant,the mixture containing urea as an additive.
 2. A seedling pot forraising root crop seedlings, the pot being a molded piece formed of amixture of an unboiled bamboo fiber, a boiled fiber of Gramineae orLeguminosae plant such as Japanese bush clover, and a carbonized plantmaterial obtained by roasting a nonwoody plant, the mixture containingin addition to urea a powder whose main component is silicon dioxide. 3.A seedling pot defined in claim 2 and having a bottom and a periphery,wherein at least one perforation is formed in either of or both thebottom and periphery.
 4. A seedling pot defined in claim 2, wherein anonwoody plant roasted to give the carbonized plant material isbuckwheat or tea dregs.
 5. A seedling pot defined in claim 1 and havinga bottom and a periphery, wherein at least one perforation is formed ineither of or both the bottom and periphery.
 6. A seedling pot defined inclaim 1, wherein a nonwoody plant roasted to give the carbonized plantmaterial is buckwheat or tea dregs.